docs: update 4-3-importing-transactions.md

[habib424]

Drafted by Ship Ship 🚢 — confidence 🟢 high

What changed

Updated the "Handling Duplicates" section to reflect that bank-feed duplicates are now hidden entirely from the reconciliation view, rather than appearing as "Excluded," so they can't be accidentally un-excluded.

Source PRs

• light#7549 — Ignore duplicated bank transactions on bank reconciliation BFF view

How to use this PR

1. Review the diff against the existing article — focus on accuracy and customer voice.
2. Merge if it reads well. Edit and push to this branch if it needs adjustment.
3. Close without merging if the article doesn't actually need this update.

Once we have a track record of clean drafts, we'll graduate to auto-merge with a delay buffer. For now: human-in-the-loop.